relationships - purpose - resilience - sleep - movement - nutrition

First things first: Despite currently very controversially discussed, fat is NOT your enemy and you don't have to shy away from it! Quite the opposite in fact! It's a non-negotiable part of a healthy diet as our body cannot create it itself, but still needs it for proper brain function (after all, 60% of the brain is fat), energy and hormone production, organ protection, body heat generation, etc. Furthermore, it doesn't just make food taste way better, it also helps with nutrient absorption and satiety.
Having said that, like pretty much everything else, fat is healthiest in its whole form. Think avocados, olives, nuts, fatty fish, eggs and whole fat dairy. Man-made fat (called "trans fats") -processed foods are typically full of them- should be avoided like the plague.
In regards to oil, you could choose based on your health goals (different oils have different fatty acid, vitamin and antioxidant profils), what you want to do with it (different oils have different smoke points and different tastes) or your budget (the price range for different oils is pretty wide depending on what it's made of and how it was extracted) OR you could simply do like me and only go with olive oil: One unrefined, cold-pressed extra virgine one for cold stuff like dressings, dipping or to drissle on top of readily cooked foods just before serving and one naturally refined one for cooking (I also like avocado oil as cooking oil for its high smoke point and neutral taste, but this is not as easily available in all stores in Europe as it is i.e. in the US).
And, because "everything is better with butter", the occasional butter for baking or to smear on -ideally freshly baked, homemade- bread is fine too (as for all dairy, grass-fed is preferred, if available to you).
That's it. So simple!